Atrios posted an item about how the Democrats should've gone into healthcare with single-payer as the benchmark, then compromised down to the public option. Ezra Klein, however, disagrees:
If President Obama had begun health reform with a speech aggressively laying out the case for single payer, the next morning's newspapers would be filled with stories suggesting that 40 Republicans and 30 Democrats had pronounced Obama's health reform effort dead on arrival. And when that got torn apart, Obama's credibility on the issue would've been substantially shredded.
I definitely agree with Ezra on this one. Single-payer is, of course, something I strongly support, but take a look at the fight against the public option from the corrupt and spineless, then multiply that times a gazillion and that's what we'd be witnessing right now had the president basically announced the complete dismantling of a trillion dollar system. As Ezra wrote, such a proposal would've almost entirely doomed healthcare reform and we'd have nothing.
The public option allows the dismantling to potentially happen in a more natural, organic fashion. Either that or it'll significantly streamline the system. It's a win-win.